1、①1-12的基数词如下：one 1, two 2, three 3, four 4, five 5, six 6, seven 7, eight 8, nine 9,ten 10, eleven 11, twelve 12.
3、③20-90等十位数均含有后缀-ty． 例如：twenty 20, thirty 30, forty 40, fifty 50, sixty 60, seventy 70, eighty80, ninety 90.
5、⑤百位数由1-9加hundred构成，如包含十位数及个位数，中间用and连接，也可以不用；如只包含个醐蛑臀谁位数，即十位数为零时，则and不可省。例如：a (one) hundred 100two hundred 200three hundred and seven 307four hundred (and) twenty-five 425five hundred (and) thirty-four 534thirteen hundred 1300 (英语中从1100-1900之间的整数常用hundred表示）
